CN112658030A - Rolling method of wide and thin high-nickel-molybdenum austenitic stainless steel plate - Google Patents
Rolling method of wide and thin high-nickel-molybdenum austenitic stainless steel plate Download PDFInfo
- Publication number
- CN112658030A CN112658030A CN202011396869.4A CN202011396869A CN112658030A CN 112658030 A CN112658030 A CN 112658030A CN 202011396869 A CN202011396869 A CN 202011396869A CN 112658030 A CN112658030 A CN 112658030A
- Authority
- CN
- China
- Prior art keywords
- rolling
- steel plate
- stainless steel
- austenitic stainless
- wide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Heat Treatment Of Steel (AREA)
- Metal Rolling (AREA)
Abstract
The invention discloses a rolling method of a wide and thin high-nickel-molybdenum austenitic stainless steel plate, which is characterized by comprising the following steps: preparing a blank, and controlling the thickness, width and length of the blank; adopting a high-temperature heating strategy; rolling by adopting a single-stand four-roller reversible rolling mill, wherein the rolling roller period is arranged in the early stage of the rolling mill; adopting a 12+1 pass and rapid steel rolling strategy; controlling the finishing temperature to be more than or equal to 850 ℃; sending the rolled steel plate to a pre-straightening machine for 2-4 times of reciprocating pre-straightening; and the rolled steel plate is air-cooled and does not need watering. According to the invention, the width of the thin high-nickel molybdenum stainless steel plate can be enlarged to 2500-3000 mm by using a heavy and medium plate mill for rolling, so that the number of welding seams of the product in use can be reduced, the cost is reduced, the safety is improved, and the service life is prolonged.
Description
Technical Field
The invention relates to a rolling production technology of stainless steel, in particular to a rolling production method of a wide and thin high-nickel-molybdenum austenitic stainless steel plate.
Background
With increasingly harsh service environments in the fields of petroleum, chemical industry, military industry, ocean development and the like, the traditional stainless steels such as 304, 316 and the like cannot meet the use requirements of special function fields. The high-nickel and high-molybdenum austenitic stainless steel has good corrosion resistance in non-oxidizing acids such as sulfuric acid, acetic acid, formic acid and phosphoric acid, good pitting corrosion resistance in a neutral chloride ion-containing medium, and good crevice corrosion resistance and stress corrosion resistance, so that the high-nickel and high-molybdenum austenitic stainless steel is widely applied to the fields of petrochemical equipment, sulfuric acid storage and transportation equipment, flue gas desulfurization devices and the like. In recent years, with the limit of the international maritime convention on the content of the sulfur oxides in the ship exhaust gas, the demand of ship flue gas desulfurization devices is increased rapidly, and the market demand for thin-gauge high-nickel-molybdenum steel is also driven.
The wider such products, the fewer the number of welds, the more cost effective and the greater the safety. However, such stainless steel has large deformation resistance at high temperature and high rolling difficulty, and is difficult to achieve a product with both thin specification and wide breadth. At present, the production of thin gauge is usually performed by hot continuous rolling, but this also limits the width of the finished product. The main stream width of wide-breadth high-nickel-molybdenum austenitic stainless steel plates in the market is less than 2 m.
Disclosure of Invention
The invention aims to solve the technical problem of overcoming the defects of the prior art and provides a rolling scheme of a wide and thin high-nickel-molybdenum austenitic stainless steel plate by using a heavy and medium plate mill. By adopting the rolling method, the high-nickel molybdenum austenitic stainless steel plate with the thickness of 8 mm-12 mm and the width of 2.5 m-3 m and the wide and thin specification can be produced.
In order to solve the technical problems, the invention specifically adopts the following technical scheme:
a rolling method of a wide and thin high-nickel-molybdenum austenitic stainless steel plate is characterized by comprising the following steps:
preparing a blank: cogging the continuous casting billet, and controlling the thickness of the billet to be 110-150 mm, the width to be 1500-2800 mm and the length to be 2050-4500 mm;
heating: a high-temperature heating strategy is adopted, the steel billet is sent to a stepping heating furnace to be heated, the total heating time is controlled according to the thickness of the steel billet in the time of 13-20 min/cm, the temperature of a soaking section is 1230-1270 ℃, the time of the soaking section is at least 25min, and the tapping temperature is controlled at 1250-1270 ℃;
rolling: rolling by adopting a single-stand four-roller reversible rolling mill, wherein the rolling roller period is arranged at the early stage of the rolling mill roller, and the number of rolled kilometers in the rolling mill roller period is less than or equal to 15 km; adopting 12+1 passes, gradually increasing the reduction rate from about 11% of the 1 st pass to 15% -29% of the 5 th pass, and then gradually decreasing, wherein the reduction rate of the 11 th pass is 13-14%, and the reduction rate of the 12 th pass is 7-9%; a rapid steel rolling strategy is adopted, the rolling speed is 1.20-2.50 m/s, and the steel throwing distance and the inter-pass interval are reduced as much as possible; controlling the finishing temperature to be more than or equal to 850 ℃;
straightening: sending the rolled steel plate to a pre-straightening machine for 2-4 times of reciprocating pre-straightening;
and (3) cooling: and the rolled steel plate is air-cooled and does not need watering.
Preferably, the thickness of the finished product of the high-nickel molybdenum austenitic stainless steel plate ranges from 8mm to 12mm, and the width ranges from 2500mm to 3000 mm.
Preferably, 2-4 common flaw detection steel plates with the width wider than that of the finished high-nickel-molybdenum austenitic stainless steel plate are arranged to be rolled before rolling, and the rolls are fully ironed.
Preferably, the entire production process is not descaled to reduce temperature drop.
Preferably, after the slab is discharged from the heating furnace and before rolling begins, in order to reduce the temperature reduction rate of the steel plate and ensure that the rolling process is finished smoothly, water cooling devices such as roller cooling water, side spraying of a rolling mill and the like are closed.
Compared with the prior art, the invention has the beneficial effects that:
at present, most of domestic high-nickel molybdenum austenitic stainless steel plates depend on import, and meanwhile, the width of a product with the thickness of 8-12 mm is basically below 2000 mm. The difficulty of preparing a product with the thickness of 8-12 mm and the width of more than 2000mm by using a medium plate mill instead of a hot continuous rolling technology is high. According to the invention, the medium plate mill is used for rolling, the width of the thin high nickel molybdenum stainless steel plate can be expanded to 2500-3000 mm through the 5m rolling range and the large reduction capacity (the maximum reduction force reaches 120000 kN in normal production) of the medium plate mill, and after a series of trial-manufacture adjustment rolling rules and reduction forces, the number of welding seams of the product in use can be reduced, the cost is reduced, the safety is increased, and the service life is prolonged.
Detailed Description
The process of the present invention is described in further detail below with reference to specific examples.
Example 1
This example provides a rolling method of a wide-width thin-gauge nickel-molybdenum austenitic stainless steel plate, selecting N08904 steel with blank size of 124mm (thickness) × 1532mm (width) × 3430mm (length), and chemical components (weight percentage): 0.01 percent of C, 0.10 percent of Mn, 0.01 percent of P, 0.01 percent of S, 0.10 percent of Si, 20.1 percent of Cr, 24.3 percent of Ni, 4.2 percent of Mo and the balance of Fe, and the steel plate with the planned rolling finished product size of 10.6mm multiplied by 2820mm multiplied by 21755 mm.
And (3) after the appearance size of the blank is inspected to be qualified, adopting a high-temperature heating strategy, and sending the steel blank to a stepping heating furnace for heating, wherein the furnace time is 218min, the temperature of a soaking section is 1264-1270 ℃, the soaking time is 29min, and the tapping temperature is 1270 ℃. And (2) rolling by adopting a single-stand four-roller reversible rolling mill, wherein the rolling roller period is arranged in the early stage of the rolling mill roller, the number of rolled kilometers in the rolling mill roller period is required to be less than or equal to 15km, and 2-4 common flaw detection steel plates with widths wider than that of the stainless steel plates are arranged before rolling to roll and fully scald the rollers. And closing the roller way cooling water and the rolling mill side-spraying water cooling devices. In order to reduce the temperature drop, the high-pressure water tank does not descale, and the high-pressure water tank does not descale in the rolling process, but the purging is started.
The rolling process is carried out for 12+1 times, the reduction rate is gradually increased from about 11% of the 1 st time to 15% -29% of the 5 th time, and then the reduction rate is gradually reduced. The reduction rate of the 11 th pass is 13-14%, and the reduction rate of the 12 th pass is 7-9%. And (3) adopting a rapid steel rolling strategy, wherein the rolling speed reaches 1.20-2.50 m/s, the steel throwing distance and the inter-pass spacing are reduced as much as possible, and the final rolling temperature is 866 ℃. And (4) opening the rolled steel plate to a pre-straightening machine for 2-4 times of reciprocating pre-straightening. After rolling, air cooling is carried out without watering. The final product size is 10.55mm x 2806mm x 21700mm, the surface is flat and the plate shape is good.
Example 2
This example provides a rolling method of a wide-width thin-gauge nickel-molybdenum austenitic stainless steel plate, selecting N08904 steel with a blank size of 123mm (thickness) × 1532mm (width) × 3597mm (length), and chemical components (weight percent): 0.01 percent of C, 0.10 percent of Mn, 0.01 percent of P, 0.01 percent of S, 0.10 percent of Si, 20.1 percent of Cr, 24.3 percent of Ni, 4.2 percent of Mo and the balance of Fe, and the steel plate with the planned rolling finished product size of 10.6mm multiplied by 2620mm multiplied by 25627 mm.
And after the appearance size of the blank is inspected to be qualified, a high-temperature heating strategy is adopted, the steel blank is sent to a stepping heating furnace to be heated, the furnace time is 223min, the temperature of a soaking section is 1267-1270 ℃, the soaking time is 36min, and the tapping temperature is 1269 ℃. The method is characterized in that a single-stand four-roller reversible rolling mill is adopted for rolling, the rolling roller period is arranged in the early stage of the rolling mill roller, the number of rolled kilometers in the rolling mill roller period is less than or equal to 15km, 2-4 common flaw detection steel plates with widths wider than that of the stainless steel plates are arranged for rolling before rolling, and the rollers are fully scalded. And after the slab is discharged from the heating furnace and before rolling begins, closing roller cooling water, rolling mill side-spraying and other water cooling devices to reduce the temperature reduction rate of the steel plate and ensure that the rolling process is finished smoothly. In order to reduce the temperature drop, the high-pressure water tank does not descale, and the high-pressure water tank does not descale in the rolling process, but the purging is started.
The rolling process is carried out for 12+1 times, the reduction rate is gradually increased from about 11% of the 1 st time to 15% -29% of the 5 th time, and then the reduction rate is gradually reduced. The reduction rate of the 11 th pass is 13-14%, and the reduction rate of the 12 th pass is 7-9%. And (3) adopting a rapid steel rolling strategy, wherein the rolling speed reaches 1.20-2.50 m/s, the steel throwing distance and the inter-pass spacing are reduced as much as possible, and the final rolling temperature is 862 ℃. And (4) opening the rolled steel plate to a pre-straightening machine for 2-4 times of reciprocating pre-straightening. After rolling, air cooling is carried out without watering. The final product has dimensions of 10.48mm × 2654mm × 24587mm, flat surface and good plate shape.
Example 3
This example provides a rolling method of a wide-width thin-gauge nickel-molybdenum austenitic stainless steel plate, selecting N08904 steel with a blank size of 122mm (thickness) × 1532mm (width) × 2920mm (length), and chemical components (weight percent): 0.01 percent of C, 0.10 percent of Mn, 0.01 percent of P, 0.01 percent of S, 0.10 percent of Si, 20.1 percent of Cr, 24.3 percent of Ni, 4.2 percent of Mo and the balance of Fe, and the steel plate with the planned rolling finished product size of 10.6mm multiplied by 2980mm multiplied by 18140 mm.
And after the appearance size of the blank is inspected to be qualified, a high-temperature heating strategy is adopted, the steel blank is sent to a stepping heating furnace to be heated, the furnace time is 218min, the temperature of a soaking section is 1260-1268 ℃, the soaking time is 25min, and the tapping temperature is 1268 ℃. And a single-stand four-roller reversible rolling mill is adopted for rolling, the rolling roller period is arranged in the roller early stage, the number of rolled kilometers in the roller period is less than or equal to 15km, and 2-4 common flaw detection steel plates with the width wider than that of the stainless steel plate are arranged for rolling before rolling, so that the rollers are fully scalded. And after the slab is discharged from the heating furnace and before rolling begins, closing roller cooling water, rolling mill side-spraying and other water cooling devices to reduce the temperature reduction rate of the steel plate and ensure that the rolling process is finished smoothly. In order to reduce the temperature drop, the high-pressure water tank does not descale, and the high-pressure water tank does not descale in the rolling process, but the purging is started.
The rolling process is carried out for 12+1 times, the reduction rate is gradually increased from about 11% of the 1 st time to 15% -29% of the 5 th time, and then the reduction rate is gradually reduced. The reduction rate of the 11 th pass is 13-14%, and the reduction rate of the 12 th pass is 7-9%. And (3) adopting a rapid steel rolling strategy, wherein the rolling speed reaches 1.20-2.50 m/s, the steel throwing distance and the inter-pass spacing are reduced as much as possible, and the final rolling temperature is 858 ℃. And (4) opening the rolled steel plate to a pre-straightening machine for 2-4 times of reciprocating pre-straightening. After rolling, air cooling is carried out without watering. The final product size is 10.57mm × 2997mm × 17655mm, the surface is flat, and the plate shape is good.
Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made thereto without departing from the spirit and scope of the invention and it is intended to cover in the claims the invention as defined in the appended claims.
Claims (5)
1. A rolling method of a wide and thin high-nickel-molybdenum austenitic stainless steel plate is characterized by comprising the following steps:
preparing a blank: cogging the continuous casting billet, and controlling the thickness of the billet to be 110-150 mm, the width to be 1500-2800 mm and the length to be 2050-4500 mm;
heating: a high-temperature heating strategy is adopted, the steel billet is sent to a stepping heating furnace to be heated, the total heating time is controlled according to the thickness of the steel billet in the time of 13-20 min/cm, the temperature of a soaking section is 1230-1270 ℃, the time of the soaking section is at least 25min, and the tapping temperature is controlled at 1250-1270 ℃;
rolling: rolling by adopting a single-stand four-roller reversible rolling mill, wherein the rolling roller period is arranged at the early stage of the rolling mill roller, and the number of rolled kilometers in the rolling mill roller period is less than or equal to 15 km; adopting 12+1 passes, gradually increasing the reduction rate from about 11% of the 1 st pass to 15% -29% of the 5 th pass, and then gradually decreasing, wherein the reduction rate of the 11 th pass is 13-14%, and the reduction rate of the 12 th pass is 7-9%; a rapid steel rolling strategy is adopted, the rolling speed is 1.20-2.50 m/s, and the steel throwing distance and the inter-pass interval are reduced as much as possible; controlling the finishing temperature to be more than or equal to 850 ℃;
straightening: sending the rolled steel plate to a pre-straightening machine for 2-4 times of reciprocating pre-straightening;
and (3) cooling: and the rolled steel plate is air-cooled and does not need watering.
2. The rolling method of the wide and thin gauge high nickel molybdenum austenitic stainless steel plate according to claim 1, wherein the finished high nickel molybdenum austenitic stainless steel plate has a thickness ranging from 8mm to 12mm and a width ranging from 2500mm to 3000 mm.
3. The method of rolling a wide and thin gauge niclcm austenitic stainless steel sheet according to claim 1, wherein 2 to 4 normal flaw detection steel sheets wider than the width of the finished niclcm austenitic stainless steel sheet are arranged to be rolled before rolling, and the rolls are sufficiently ironed.
4. The method of rolling a wide width thin gauge nickel-molybdenum-rich austenitic stainless steel sheet according to claim 1, wherein the entire process is not descaled.
5. The method for rolling a wide and thin gauge high nickel molybdenum austenitic stainless steel plate according to claim 1, wherein after the slab is discharged from the heating furnace and before the rolling is started, the roller cooling water and the rolling mill side water cooling device are shut down.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202011396869.4A CN112658030A (en) | 2020-12-03 | 2020-12-03 | Rolling method of wide and thin high-nickel-molybdenum austenitic stainless steel plate |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202011396869.4A CN112658030A (en) | 2020-12-03 | 2020-12-03 | Rolling method of wide and thin high-nickel-molybdenum austenitic stainless steel plate |
Publications (1)
Publication Number | Publication Date |
---|---|
CN112658030A true CN112658030A (en) | 2021-04-16 |
Family
ID=75402379
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202011396869.4A Pending CN112658030A (en) | 2020-12-03 | 2020-12-03 | Rolling method of wide and thin high-nickel-molybdenum austenitic stainless steel plate |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN112658030A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114042773A (en) * | 2021-10-18 | 2022-02-15 | 山西太钢不锈钢股份有限公司 | Method for improving structure uniformity of stainless steel extra-thick plate |
CN114130816A (en) * | 2021-10-31 | 2022-03-04 | 张家港宏昌钢板有限公司 | Staged plate rolling production method suitable for 3500mm medium and heavy plate mill |
CN114405997A (en) * | 2022-01-19 | 2022-04-29 | 南京钢铁股份有限公司 | Production method of thin steel plate |
CN115990746A (en) * | 2023-03-22 | 2023-04-21 | 江苏省沙钢钢铁研究院有限公司 | Ultra-thin ultra-wide steel plate and production method thereof |
CN116618435A (en) * | 2023-04-03 | 2023-08-22 | 江苏沙钢集团有限公司 | Production and manufacturing method of extreme thin steel plate |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101898200A (en) * | 2009-12-16 | 2010-12-01 | 安徽工业大学 | Direct rolling method of zinc ingots |
CN103272843A (en) * | 2013-06-19 | 2013-09-04 | 济钢集团有限公司 | Production and rolling method for 4-5mm ultra-thin slabs |
CN110756580A (en) * | 2019-10-15 | 2020-02-07 | 南京钢铁股份有限公司 | Rolling method of wide and thin 6Mo super austenitic stainless steel plate |
CN110773565A (en) * | 2019-09-23 | 2020-02-11 | 南京钢铁股份有限公司 | Method for rolling super austenitic stainless steel |
CN111389928A (en) * | 2020-03-30 | 2020-07-10 | 南京钢铁股份有限公司 | Method for producing ultrathin and ultra-wide limit specification nuclear power steel by wide and thick plate rolling mill |
CN111889512A (en) * | 2020-08-12 | 2020-11-06 | 宝武集团鄂城钢铁有限公司 | Method for producing thin steel plate by single-stand rolling mill |
-
2020
- 2020-12-03 CN CN202011396869.4A patent/CN112658030A/en active Pending
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101898200A (en) * | 2009-12-16 | 2010-12-01 | 安徽工业大学 | Direct rolling method of zinc ingots |
CN103272843A (en) * | 2013-06-19 | 2013-09-04 | 济钢集团有限公司 | Production and rolling method for 4-5mm ultra-thin slabs |
CN110773565A (en) * | 2019-09-23 | 2020-02-11 | 南京钢铁股份有限公司 | Method for rolling super austenitic stainless steel |
CN110756580A (en) * | 2019-10-15 | 2020-02-07 | 南京钢铁股份有限公司 | Rolling method of wide and thin 6Mo super austenitic stainless steel plate |
CN111389928A (en) * | 2020-03-30 | 2020-07-10 | 南京钢铁股份有限公司 | Method for producing ultrathin and ultra-wide limit specification nuclear power steel by wide and thick plate rolling mill |
CN111889512A (en) * | 2020-08-12 | 2020-11-06 | 宝武集团鄂城钢铁有限公司 | Method for producing thin steel plate by single-stand rolling mill |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114042773A (en) * | 2021-10-18 | 2022-02-15 | 山西太钢不锈钢股份有限公司 | Method for improving structure uniformity of stainless steel extra-thick plate |
CN114042773B (en) * | 2021-10-18 | 2023-06-23 | 山西太钢不锈钢股份有限公司 | Method for improving tissue uniformity of stainless steel super-thick plate |
CN114130816A (en) * | 2021-10-31 | 2022-03-04 | 张家港宏昌钢板有限公司 | Staged plate rolling production method suitable for 3500mm medium and heavy plate mill |
CN114130816B (en) * | 2021-10-31 | 2024-02-13 | 张家港宏昌钢板有限公司 | Staged rolled plate production method suitable for 3500mm medium plate mill |
CN114405997A (en) * | 2022-01-19 | 2022-04-29 | 南京钢铁股份有限公司 | Production method of thin steel plate |
CN114405997B (en) * | 2022-01-19 | 2024-03-19 | 南京钢铁股份有限公司 | Production method of thin steel plate |
CN115990746A (en) * | 2023-03-22 | 2023-04-21 | 江苏省沙钢钢铁研究院有限公司 | Ultra-thin ultra-wide steel plate and production method thereof |
CN115990746B (en) * | 2023-03-22 | 2023-06-06 | 江苏省沙钢钢铁研究院有限公司 | Ultra-thin ultra-wide steel plate and production method thereof |
CN116618435A (en) * | 2023-04-03 | 2023-08-22 | 江苏沙钢集团有限公司 | Production and manufacturing method of extreme thin steel plate |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN112658030A (en) | Rolling method of wide and thin high-nickel-molybdenum austenitic stainless steel plate | |
CN110819877B (en) | Method for producing ultra-pure ferrite stainless steel for decoration by using steckel mill | |
CN103212571B (en) | Method for producing oxide scale capable of preventing steel plate surface from getting rusty | |
CN110756580B (en) | Rolling method of wide and thin 6Mo super austenitic stainless steel plate | |
AU2019219859B2 (en) | Corrosion-resistant rail and manufacturing method thereof | |
CN103710507B (en) | A kind of preparation method of low nickel duplex stainless steel hot-rolled sheet coil | |
CN110484817A (en) | A method of eliminating ultra-wide economizing type two phase stainless steel surface crack of plate | |
CN103962386A (en) | Oxide scale control method for improving corrosion resistance of hot rolled medium plate | |
CN113403462B (en) | Preparation method of green-peel steel with yield strength of 700-1000 MPa | |
CN110453148A (en) | A kind of ultra-wide economizing type two phase stainless steel cut deal and its manufacturing method | |
CN107649522A (en) | Surface quality of hot rolled steel coils control method | |
CN110629129B (en) | Flexible manufacturing method capable of simultaneously producing X52 and X60 grade pipeline steel | |
CN102921750A (en) | Method for removing bright trace on surface of strip steel | |
CN114875339A (en) | Low-density cold-rolled thin steel strip with short process, low energy consumption and high tensile strength and manufacturing method thereof | |
CN112126855A (en) | Production method of cold-rolled weather-resistant steel with yield strength of more than 310MPa | |
CN114558888A (en) | Solution-free annealing production method for stainless steel hot-rolled steel strip | |
CN105032974A (en) | Production method of zirconium and zirconium alloy strip coil | |
CN115216710B (en) | Production method of low-density steel with tensile strength more than or equal to 2000MPa based on strip continuous casting | |
CN113020911B (en) | Preparation method of austenitic stainless steel matte product | |
CN113355496B (en) | On-line solution annealing process for rolling waste heat of stainless steel hot-rolled coil | |
CN112317547A (en) | Method for rolling wide Ni-Fe-Cr heat-resistant alloy thick plate | |
CN108504834A (en) | A kind of production method of Mo ultralow-carbon martensitic stainless steel cut deal | |
CN114686751B (en) | Brittle failure prevention production method for high-chromium ferrite stainless steel | |
CN112355051A (en) | Rolling method of high-surface-quality marine steel plate | |
CN111069285A (en) | Asynchronous hot continuous rolling method for preparing hot-rolled extremely-thin steel strip |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210416 |
|
RJ01 | Rejection of invention patent application after publication |